ffmpeg

http://ubuntuforums.org/showthread.php?t=786095 - Ubuntu HOWTO: Install and use the latest FFmpeg and x264
http://rob.opendot.cl/index.php/useful-stuff/psp-video-guide/
http://juliensimon.blogspot.com/2009/01/howto-ffmpeg-x264-presets.html
http://www.haykranen.nl/2007/11/21/howto-install-and-use-ffmpeg-on-mac-os-x-leopard/
http://stephenjungels.com/jungels.net/articles/ffmpeg-howto.html
http://goinggnu.wordpress.com/2007/02/13/convert-avi-to-3gp-using-ffmpeg/
http://codesnippets.joyent.com/posts/show/2021
http://oddmanout.wordpress.com/2008/01/26/converting-an-mkv-h264-file-to-ps3-mp4-without-re-encoding-on-mac-os-x/
http://ffmpegx.com/download.html

Android convert:
ffmpeg -i input.avi -f mp4 -vcodec mpeg4 -s qvga -r 25 -b 900k -acodec aac -ac 2 -ar 24000 -ab 128k -strict experimental output.mp4